feat: Setup development environment

The environment includes java, maven, IntelliJ and a postgres server.

devenv.nix

@@ -0,0 +1,70 @@
+{
+  pkgs,
+  lib,
+  config,
+  inputs,
+  ...
+}:
+
+{
+  imports = [ ];
+
+  # https://devenv.sh/packages/
+  packages = [
+    pkgs.git
+    pkgs.jetbrains.idea-community-bin
+  ];
+
+  languages.java.enable = true;
+  languages.java.maven.enable = true;
+  languages.nix.enable = true;
+
+  # https://devenv.sh/processes/
+  # processes.cargo-watch.exec = "cargo-watch";
+
+  processes.flexinale-monolith.exec = ''
+    java -Dspring.datasource.url=jdbc:postgresql://localhost:5432/monolith -jar flex-training-flexinale/flexinale-monolith/target/flexinale-monolith-2024.3.0-spring-boot-fat-jar.jar
+  '';
+
+  # https://devenv.sh/services/
+  services.postgres = {
+    enable = true;
+    listen_addresses = "127.0.0.1";
+    initialScript =
+      let
+        createDB = n: ''
+          CREATE DATABASE "${n}";
+          GRANT ALL PRIVILEGES ON DATABASE "${n}" TO "flexinale";
+        '';
+      in
+      ''
+        CREATE USER flexinale WITH SUPERUSER PASSWORD 'flexinale';
+      ''
+      + (lib.strings.concatMapStringsSep "\n" createDB [
+        "monolith"
+        "modulith-1"
+        "modulith-2"
+        "distributed-backoffice"
+        "distributed-besucherportal"
+        "distributed-ticketing"
+        "distributed-test"
+      ]);
+  };
+
+  # https://devenv.sh/scripts/
+  scripts.monolith-load.exec = ''
+    cd ${config.env.DEVENV_ROOT}/flex-training-flexinale
+    mvn test -Dtest=testdata.TestDataLoader -pl flexinale-monolith -am
+  '';
+
+  # https://devenv.sh/tests/
+  enterTest = ''
+    echo "Running tests"
+    git --version | grep --color=auto "${pkgs.git.version}"
+  '';
+
+  # https://devenv.sh/pre-commit-hooks/
+  pre-commit.hooks.shellcheck.enable = true;
+
+  # See full reference at https://devenv.sh/reference/options/
+}